The World Wide Web of the Internet is the most successful distributed application in the history of computing. In the Web environment, client machines effect transactions to Web servers use the Hypertext Transfer Protocol (HTTP), which is a known application protocol providing users access to files (e.g., text, graphics, images, sound, video, etc.) using a standard page description language known as Hypertext Markup Language (HTML). HTML provides basic document formatting and allows the developer to specify "links" to other servers and files. In the Internet paradigm, a network path to a server is identified by a so-called Uniform Resource Locator (URL) having a special syntax for defining a network connection. Use of an HTML-compatible browser (e.g., Netscape Navigator or Microsoft Internet Explorer) at a client machine involves specification of a link via the URL. In response, the client makes a request to the server identified in the link and receives in return a document formatted according to HTML.
There has been great interest in providing Internet access at minimal economic cost. While most computers now are pre-configured for Internet access, a significant percentage of households still do not have a personal computer. Thus, it has now been proposed to provide a data processing system that, much like a VCR, may be connected to a television set and used in lieu of a personal computer to provide Web access through a conventional remote control device associated with the system unit. Such a system enables the television to become, in effect, a "Web" appliance. The viewer can rapidly switch between conventional television and Internet access using the remote control unit. All of the conventional "Internet" access tools and navigational functions are preferably "built-in" to the system and thus hidden to the user.
One such tool is so-called "off-line" browsing. As any casual user of the Internet can attest, interesting or attractive web sites are sometimes difficult to access due to large traffic demands. As a result, several companies have developed so-called "off-line" browser programs that are designed to deliver web pages from favorite Web servers to a user's hard drive for browsing at the user's convenience. Typically, such programs include some form of scheduling feature that enables the user to fetch identifiable pages at off-peak hours, saving time and connection charges. The user may then browse the pages at his or her convenience without a modem and even without an active connection to the Internet.
While off-line browser programs offer certain advantages, they do not have the capability to optimize utilization of the communication link between the client and the World Wide Web during the off-peak information retrieval process. This problem becomes more acute if there are constraints on the amount of time that off-peak information retrieval may be accomplished. In the future, it is anticipated that Web appliances of the type described above will be provided by computer network or other service providers, who will only allow their subscribers limited periods of time during which off-line browsing will be permitted. Thus, for example, a network operator may restrict subscribers to off-line browsing for just one hour per night. During this hour, a user may desire to obtain content from numerous Web sites. Thus, it would be desirable to provide some mechanism that could optimize retrieval of Web content during this limited period of time.
The present invention addresses and solves this important problem.